1. Field of the Invention
The present invention relates to a panel member control system.
2. Description of Related Art
A device (e.g., a power window device and a sunroof device for a vehicle) for driving an opening/closing member to be opened/closed conventionally performs automatic reverse control on detecting pinching of a foreign object in the opening/closing member. In pinching detection processing of such a device, a variation (e.g., variations in a rotation speed of a drive motor, in a variability rate, and in a movement speed of the opening/closing member), which is caused by the pinching of the foreign object, is calculated. Then, it is determined that the pinching is produced when this variation exceeds a predetermined pinching determination threshold.
Taking the power window device for example, an external load (a disturbance) is applied due to vibration when a vehicle door is opened/closed or while the vehicle is running. Particularly while driving on a rough road, a heavy external load is applied. As in the case of the pinching, the external load prevents a motor from driving a windowpane to be closed, thereby sometimes causing the variation, which results in reduction in the rotation speed of the motor. Accordingly, the power window device has a disadvantage that it operates reversely due to erroneous detection of the pinching during the course of closing the windowpane when the vehicle door is opened/closed or while the vehicle is running.
In order to avoid such erroneous detection, the pinching determination threshold is changed to a larger value to lower a sensitivity to the variation is for a certain amount of time when the disturbance is detected.
For instance, a windowpane control device that is described in JP2002-96632A determines that the pinching is caused when a predetermined period of duration elapses after a decrease in a rotation speed of a power window motor becomes equal to or larger than the pinching determination threshold. A small pinching determination threshold and a short period of duration (i.e., a normal sensitivity) are employed while the vehicle is running on a normal road, whereas a large pinching determination threshold and a long period of duration (i.e., a lowered sensitivity) are employed while the vehicle is running on the rough road.
Generally, the rotation speed of the motor varies according to the vibration and an impact, which result from the vehicle running on the rough road. The windowpane control device in JP2002-96632A determines that the vehicle is running on the rough road when the rotation speed of the motor is increased to such an extent that it is equal to or larger than a predetermined set value, based on the impact that results from the vehicle running on the rough road.
Furthermore, while the vehicle is running on the rough road, even if the rotation speed of the motor becomes equal to or smaller than the set value after it exceeds the set value, the pinching determination threshold for the rough road continues to be employed until the certain amount of time elapses.
In this manner, since the windowpane control device in JP2002-96632A employs the large pinching determination threshold and the long period of duration while the vehicle is running on the rough road, the possibility of the erroneous detection of the pinching can be decreased.
As well, a power window system in JP2002-250175A sets the pinching determination threshold by subtracting a correction value that is set according to a predetermined value and a road condition, from an estimate value (an estimated rotation speed) of the rotation speed of the motor, which is calculated from a power supply voltage of the motor. Then, the power window system operates reversely on detecting the pinching when an actual measurement value of the rotation speed of the motor is below the pinching determination threshold.
In this manner, because the power window system in JP2002-250175A corrects the pinching determination threshold using the correction value that is properly set according to the road condition while the vehicle is running on the rough road, the possibility of the erroneous detection of the pinching can be decreased.
Nevertheless, in the windowpane control device in JP2002-96632A, if the period of duration, which is used for determining the pinching while the vehicle is running on the rough road, is set at a relatively large value, there is likely to be a period, during which the pinching cannot be detected immediately after the vehicle runs past the rough road. Also, vibration that lasts longer than the period of duration is likely to be erroneously determined to be the pinching, if the period of duration is set at a relatively small value. Moreover, there is a disadvantage that a load used for the reverse operation remains large for a while even after the vehicle resumes running on the normal road from the rough road, if the period, during which the pinching determination threshold for the rough road is continuously employed, is set at a relatively large value.
Besides, although the power window system in JP2002-250175A properly changes the correction value according to a variation in the road condition, the pinching determination threshold does not change so as to follow a variation in the actual measurement value of the rotation speed of the motor. Hence, there is a disadvantage that the load used for the reverse operation needs to be set at a relatively large value in order to avoid an erroneous determination.